A device of this type known in practice is used in particular for locking down pallets. In such securing of pallets a draw-down bolt on the lower side of the pallet fits between the jaws of the collet chuck to secure the pallet, to which end the collet chuck must be held in the open position by the release piston, which necessitates a corresponding application of pressure on the release piston in the piston chamber. When the draw-down bolt engages between the jaws, the tension must be positively activated by switching off the release pressure, so that the tension spring can shift the release piston with the actuating member and thus close the collet chuck.